This invention concerns an improved process of preparing isomers of caryophyllene alcohols and dihydro caryophyllene alcohols. More specifically, this invention is concerned with preparation of a specific isomer mixture range of caryophyllene alcohols and dihydro caryophyllene alcohols by means of the catalytic isomerization of caryophyllene oxide and dihydro caryophyllene oxide.
Swiss Pat. No. 549,960, issued on Apr. 30, 1974, as well as U.S. Pat. Nos. 4,014,350 (issued on Mar. 29, 1977); 3,840,023 (issued on Oct. 8, 1974) and 3,937,228 (issued on Feb. 10, 1976) disclose the organoleptic utility of isomers of caryophyllene alcohol produced according to our invention in oriental tobacco. The structures of these caryophyllene alcohol isomers are: ##STR1##
It is indicated in said Swiss Pat. No. 549,960 that these materials may be prepared according to the procedure set forth in Helv. Chim. Acta, 51,494 (1968) Schulte-Elte and Ohloff. In this article it is indicated that the dyesensitized photooxygenation of isocaryophyllene leads to formation of several alcohols having the structures: ##STR2##
The reaction to convert caryophyllene oxide to various isomer mixtures of alcohols is also disclosed in Tetrahedron 27, 635 (1971) and Tetrahedron Letters 8 659 (1971) whereby the reaction: ##STR3## is carried out; in Tetrahedron 27 using an aluminum oxide catalyst and in Tetrahedron Letters 8 using a pyridinium bromide/ pyridine catalyst system.
Nothing in the prior art, however, discloses our process for producing the caryophyllene alcohol isomer mixtures or the dihydro caryophyllene alcohol mixtures of our invention whereby a fast commercially feasible reaction takes place without the use of any noxious solvents (e.g., pyridine) and nothing in the prior art discloses the specific reaction product mixtures produced according to the process of our invention.